An expansion joint is a gap that is purposely provided between adjacent concrete structures for accommodating dimensional changes to the adjacent concrete structures occurring as expansion and contraction due to temperature changes, seismic cycling, and vibration. An expansion joint may be damaged by the ingress of water and debris, by abrasion, and by shear, tensile and compression forces generated by the passage of motorized vehicular traffic across the joint.
Elongated metal plates placed in an end-to-end relationship have been bolted to concrete structures in an attempt to protect the expansion joint from damage due to pedestrian and vehicular traffic. Often, the metal plates become deformed and do not form a uniform seated engagement with concrete structures, particularly where the traffic bearing upper surfaces of the adjacent concrete structures are irregular or undulating and therefore fail to provide the necessary uniform planar support for the metal plates. Under these conditions, the metal plates are bent and distorted due to impact loading of traffic and acquire a state of looseness about their mounting bolts which degrades further when the mounting bolts bend or break. Even before the metal plates become disjointed from the mounting bolts, the metal plates generate an annoying noise with each deflection against the adjoining concrete structures.
Additionally, it is widely known that the surfaces of concrete structural members are not always entirely uniform, and are often not produced with square or smooth surfaces. These concrete structural members are usually rough, often have substantially irregular or undulating gaps, or are missing entire chunks of concrete. Furthermore, there is often a vertical offset between two structural members, due to the settlement of concrete.
Therefore, a need exists in the art for an improved cover assembly to extend across gaps or openings between spaced-apart structural members to protect the expansion joint from degradation and to provide a smooth transition across the expansion joint opening.